bread yeast working

[MARCELO178]

12 days ago I made a weissbier with bread yeast. I never have used bread yeast before and after 12 days the CO2 keeps going out. I never had a beer that released CO2 for such a long time. Some people told me the bread yeast works very slowly. I am afraid of a contamination. But I don´t see signs of bacterial contamination. Despite the yeast is still floating on the top, the beer looks clear for a weissbier.
Is there anybody with bread yeast experience to give me an advice?

 

[MalFet]

Bread yeast is generally bred to start rising quickly. In beer terms, that means a short lag time but also a smaller peak population of cells. That's likely what's giving you the slower-than-usual fermentation.

At the same time, unless you've taken a hydro reading (which I assume you didn't since you didn't mention it), you don't actually know that the fermentation is still happening. You might just be bleeding off super-saturated CO2 slowly.

 

[MARCELO178]

I think you are probably right, it´s been 14 days now and CO2 is still going out. I raised the temperature, in the beginning it was about 18 C(64.4F), I raised to 22C (71.6F) and now it is in 25C (77F). there is no foam but the yeast is on the top, in 2 weeks normally all yeast that I used before went down.
I have an idea to confirm your theory about super-saturated CO2. if I lower the temperature it will probably suck the airlock. What do you think?

 

[Denny's Evil Concoctions]

Take a hydrometer reading.

 

[MalFet]

I think you are probably right, it´s been 14 days now and CO2 is still going out. I raised the temperature, in the beginning it was about 18 C(64.4F), I raised to 22C (71.6F) and now it is in 25C (77F). there is no foam but the yeast is on the top, in 2 weeks normally all yeast that I used before went down.
I have an idea to confirm your theory about super-saturated CO2. if I lower the temperature it will probably suck the airlock. What do you think?

Yeah, don't do that. I'm not sure why that would test for excess CO2, and if your yeast are still working a temperature drop will possibly crash them out. Use a hydrometer or wait it out.